On Tue, Nov 26 2013, david at tethera.net wrote: > From: David Bremner <david at tethera.net> > > Unfortunately old versions of GCC and clang do not provide byte order > macros, so we re-invent them.
Brief comments inline :D > > If UTIL_BYTE_ORDER is not defined, we fall back to macros supported by > recent versions of GCC and clang This is not entirely accurate as -DUTIL_BYTE_ORDER=... is given to compiler... maybe If UTIL_BYTE_ORDER is not defined, empty or zero (?) > --- > > I pushed the series > id:1385328583-24602-1-git-send-email-david at tethera.net; unfortunately > that broke compilation on old versions of GCC, in particular on our > buildbot. Here is a proposed fix for the fix. > > configure | 26 ++++++++++++++++++++++++-- > lib/libsha1.c | 19 +++++-------------- > util/endian-util.h | 39 +++++++++++++++++++++++++++++++++++++++ > 3 files changed, 68 insertions(+), 16 deletions(-) > create mode 100644 util/endian-util.h > > diff --git a/configure b/configure > index 1a8e939..02d6396 100755 > --- a/configure > +++ b/configure > @@ -441,6 +441,21 @@ else > EOF > fi > > +printf "Checking byte order... " > +cat> _byteorder.c <<EOF > +#include <stdio.h> > +#include <stdint.h> > +#include <string.h> > +uint32_t test = 0x31323334; > +char buf[5]; > +int main() { memcpy(buf, &test, 4); buf[4] = '\0'; printf("%s\n", buf); > return 0; } > +EOF > +${CC} ${CFLAGS} _byteorder.c -o _byteorder > /dev/null 2>&1 > +util_byte_order=$(./_byteorder) > +echo $util_byte_order Austin version with 0x34333231 > + > +#rm -f _byteorder _byteorder.c > + > if [ $errors -gt 0 ]; then > cat <<EOF > > @@ -702,6 +717,9 @@ prefix = ${PREFIX} > # LIBDIR_IN_LDCONFIG value below is still set correctly. > libdir = ${LIBDIR:=\$(prefix)/lib} > > +# byte order within a 32 bit word. 4321 = little, 1234 = big, 0 = guess > +UTIL_BYTE_ORDER = ${util_byte_order} > + > # Whether libdir is in a path configured into ldconfig > LIBDIR_IN_LDCONFIG = ${libdir_in_ldconfig} > > @@ -807,7 +825,9 @@ CONFIGURE_CFLAGS = -DHAVE_GETLINE=\$(HAVE_GETLINE) > \$(GMIME_CFLAGS) \\ > -DHAVE_STRSEP=\$(HAVE_STRSEP) \\ > -DSTD_GETPWUID=\$(STD_GETPWUID) \\ > -DSTD_ASCTIME=\$(STD_ASCTIME) \\ > - -DHAVE_XAPIAN_COMPACT=\$(HAVE_XAPIAN_COMPACT) > + -DHAVE_XAPIAN_COMPACT=\$(HAVE_XAPIAN_COMPACT) \\ > + -DUTIL_BYTE_ORDER=\$(UTIL_BYTE_ORDER) > + > CONFIGURE_CXXFLAGS = -DHAVE_GETLINE=\$(HAVE_GETLINE) \$(GMIME_CFLAGS) \\ > \$(TALLOC_CFLAGS) -DHAVE_VALGRIND=\$(HAVE_VALGRIND) \\ > \$(VALGRIND_CFLAGS) \$(XAPIAN_CXXFLAGS) \\ > @@ -815,6 +835,8 @@ CONFIGURE_CXXFLAGS = -DHAVE_GETLINE=\$(HAVE_GETLINE) > \$(GMIME_CFLAGS) \\ > -DHAVE_STRSEP=\$(HAVE_STRSEP) \\ > -DSTD_GETPWUID=\$(STD_GETPWUID) \\ > -DSTD_ASCTIME=\$(STD_ASCTIME) \\ > - -DHAVE_XAPIAN_COMPACT=\$(HAVE_XAPIAN_COMPACT) > + -DHAVE_XAPIAN_COMPACT=\$(HAVE_XAPIAN_COMPACT) \\ > + -DUTIL_BYTE_ORDER=\$(UTIL_BYTE_ORDER) > + > CONFIGURE_LDFLAGS = \$(GMIME_LDFLAGS) \$(TALLOC_LDFLAGS) \$(XAPIAN_LDFLAGS) > EOF > diff --git a/lib/libsha1.c b/lib/libsha1.c > index 87c7c52..3566ed7 100644 > --- a/lib/libsha1.c > +++ b/lib/libsha1.c > @@ -34,7 +34,7 @@ > */ > > #include <string.h> /* for memcpy() etc. */ > - > +#include "endian-util.h" > #include "libsha1.h" > > #if defined(__cplusplus) > @@ -49,20 +49,11 @@ extern "C" > > #define bswap_32(x) ((rotr32((x), 24) & 0x00ff00ff) | (rotr32((x), 8) & > 0xff00ff00)) > > -/* The macros __BYTE_ORDER__ and __ORDER_*_ENDIAN__ are GNU C > - * extensions. They are also supported by clang as of v3.2 */ > - > -#ifdef __BYTE_ORDER__ > -# if (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) > -# define bsw_32(p,n) \ > - { int _i = (n); while(_i--) ((uint32_t*)p)[_i] = > bswap_32(((uint32_t*)p)[_i]); } > -# elif (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) > -# define bsw_32(p,n) > -# else > -# error "unknown byte order" > -# endif > +#if (UTIL_BYTE_ORDER == UTIL_ORDER_LITTLE_ENDIAN) > +# define bsw_32(p,n) \ > + { int _i = (n); while(_i--) ((uint32_t*)p)[_i] = > bswap_32(((uint32_t*)p)[_i]); } > #else > -# error "macro __BYTE_ORDER__ is not defined" > +# define bsw_32(p,n) > #endif I'd keep the BIG_ENDIAN check too, as we don't know what would happen w/ PDP_ENDIAN... > > #define SHA1_MASK (SHA1_BLOCK_SIZE - 1) > diff --git a/util/endian-util.h b/util/endian-util.h > new file mode 100644 > index 0000000..cbecf66 > --- /dev/null > +++ b/util/endian-util.h > @@ -0,0 +1,39 @@ > +/* this file mimics the macros present in recent GCC and CLANG */ > + > +#ifndef _ENDIAN_UTIL_H > +#define _ENDIAN_UTIL_H > + > +/* This are prefixed with UTIL to avoid collisions > + * > + * You can use something like the following to define UTIL_BYTE_ORDER > + * in a configure script. > + */ > +#if 0 > +#include <stdio.h> > +#include <stdint.h> > +#include <string.h> > +uint32_t test = 0x31323334; > +char buf[5]; > +int main() { memcpy(buf, &test, 4); buf[4] = '\0'; printf("%s\n", buf); > return 0; } > +#endif The "fixed simpler version" version, or just reference configure. > + > +#define UTIL_ORDER_LITTLE_ENDIAN 4321 > +#define UTIL_ORDER_BIG_ENDIAN 1234 swap :D > + > + > +#if !defined(UTIL_BYTE_ORDER) || ((UTIL_BYTE_ORDER != > UTIL_ORDER_LITTLE_ENDIAN) && \ > + (UTIL_BYTE_ORDER != > UTIL_ORDER_LITTLE_ENDIAN)) for "guess" this needs to be #if !UTIL_BYTE_ORDER || ((UTIL_BYTE... ... as UTIL_BYTE_ORDER could be defined as 0 (or empty?) in configure. $ gcc -dM -DUTIL_BYTE_ORDER= -E - </dev/null | grep -i util #define UTIL_BYTE_ORDER Tomi > +#ifdef __BYTE_ORDER__ > +# if (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) > +# define UTIL_BYTE_ORDER UTIL_ORDER_LITTLE_ENDIAN > +# elif (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) > +# define UTIL_BYTE_ORDER UTIL_ORDER_BIG_ENDIAN > +# else > +# error "Unsupported __BYTE_ORDER__" > +# endif > +#else > +# error "UTIL_BYTE_ORDER not correctly defined and __BYTE_ORDER__ not > defined." > +#endif > +#endif > + > +#endif > -- > 1.8.4.2